?? sumsq_sse2.c
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/* Compute the sum of the squares of a vector of signed shorts * The SSE2 and MMX assist routines both operate on multiples of * 8 words; they differ only in their alignment requirements (8 bytes * for MMX, 16 bytes for SSE2) * Copyright 2004 Phil Karn, KA9Q * May be used under the terms of the GNU Lesser Public License (LGPL) */long long sumsq_sse2_assist(signed short *,int);long long sumsq_sse2(signed short *in,int cnt){ long long sum = 0; /* Handle stuff before the next 8-byte boundary */ while(((int)in & 15) != 0 && cnt != 0){ sum += (long)in[0] * in[0]; in++; cnt--; } sum += sumsq_sse2_assist(in,cnt); in += cnt & ~7; cnt &= 7; /* Handle up to 7 trailing words */ while(cnt != 0){ sum += (long)in[0] * in[0]; in++; cnt--; } return sum;}
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